DE102009057665A1 - Internal combustion engine and method for operating such an internal combustion engine - Google Patents

Abstract

The invention relates to an internal combustion engine (10) in V-construction with a crankcase (12) and with two, an angle enclosing and at least one working space (24), in particular a cylinder (24), the internal combustion engine (10) having working space housings (16 , 18), in particular cylinder housings (16, 18), wherein the respective working space housing (16, 18) is movable relative to the crankcase (12), and a method for operating a V-type internal combustion engine (10) with a crankcase (12 ) and with two, an angle enclosing and in each case at least one working space (24), in particular a cylinder (24), the internal combustion engine (10) having working space housings (16, 18), in particular cylinder housings (16, 18), wherein the respective working space housing ( 16, 18) for adjusting variable compression ratios relative to the crankcase (12) is moved.

Description

The invention relates to an internal combustion engine specified in the preamble of claim 1 and a method for operating such an internal combustion engine specified in the preamble of claim 9 Art.

The EP 1 245 803 A1 discloses an internal combustion engine having an engine block with at least one cylinder and with a crankshaft having at least one crank and rotatably supported in the engine block. The crankshaft is supported by bearings, which are arranged in adjustable eccentrics. Rotation of the eccentric causes relative adjustment of the center axis of the crankshaft relative to the engine block so as to adjust the compression ratio of a piston in the cylinder.

This setting of the compression ratio involves the disadvantage that moving parts are affected, which means a high cost and therefore high costs in terms of the storage of these parts. This also negatively affects the reliability of these parts. In addition, such adjustment of the variable compression ratio in V-type internal combustion engines is very disadvantageous because cylinders of one cylinder bank are then operated at a different compression ratio than cylinders of the other cylinder bank.

It is therefore an object of the present invention to provide a V-type internal combustion engine and a method for operating such an internal combustion engine, which allow improved adjustability of the compression ratio of the internal combustion engine.

This object is achieved by a combustion engine in V-construction with the features of patent claim 1 and by a method for operating such an internal combustion engine with the features of claim 9. Advantageous embodiments with expedient and non-trivial developments of the invention are specified in the dependent claims.

A combustion engine according to the invention in V-construction with a crankcase and with two, an angle and at least one working space, in particular a cylinder, the internal combustion engine having working space housings, in particular cylinder housings, is provided by the fact that the respective working space housing is movable relative to the crankcase.

By this mobility of the respective working space housing, for example, parallel to the respective longitudinal extension of the respective working space and thus at least substantially along the enclosed by the cylinder housing angle, an adjustment of different compression ratios of the internal combustion engine is possible without changing moving parts in their position, or intervene in their bearings. In particular, the axis of rotation of the crankshaft remains unchanged in position and thus, for example, always coaxial with the axis of rotation of the transmission input shaft of a conventionally fixed in the vehicle built-in transmission. As a result, it is possible to dispense with a transmission that is movably mounted in the vehicle or with an offset compensation gearbox between the crankshaft and the transmission input shaft. This keeps on the one hand the effort to represent the different compression ratios within limits, which is associated with low cost of the internal combustion engine and / or the transmission. On the other hand, the internal combustion engine with the variable compression ratio high reliability or conversely a low probability of failure due to the low complexity, in particular compared to the prior art.

In the internal combustion engine according to the invention, for example, a crankshaft of the internal combustion engine in the crankcase derselbigen storable or stored, wherein the relative position to the crankcase and thus the position of their corresponding bearing for displaying the adjustable compression ratio is not changed.

The respective working space housing is movable, for example, by means of at least one eccentric device assigned to the respective working space housing, wherein the eccentric devices are set in relation to one another according to the angle enclosed by the working space housing. As a result, the working chamber housings are moved relative to the crankcase during an adjustment of the eccentric devices by substantially equal amounts. In both working space housings thus the same compression ratio is set. The eccentric devices are advantageously arranged coaxially to the crankshaft, which keeps the space requirement of the internal combustion engine according to the invention low. This avoids package problems, especially in a space-critical area such as an engine compartment of a motor vehicle.

Advantageously, the eccentric devices on the at least partially received by the crankcase crankshaft, in particular on corresponding journal of the Crankshaft, supported, for example, the respective working space housing is associated with a respective journal of the crankshaft. This means that the eccentric devices are arranged between the crankshaft and the work space housings, whereby a direct flow of force between the crankshaft and the work space housings is shown. This direct power flow means a very cheap power line through the internal combustion engine, which is the reliability and thus the low probability of failure beneficial.

The mentioned eccentric devices can be actuated by means of a corresponding actuator, that is rotatable, to represent the different compression ratios.

Likewise, it can be provided that the eccentric devices are mounted on the crankshaft, in particular on a respective journal, in order to design a defined and fixed support and to realize a small space requirement of the internal combustion engine according to the invention.

To ensure a uniform movement of the working space housing relative to the crankcase, at least one torque support device is provided between the working space housings and the crankcase.

If the internal combustion engine has at least one working chamber housing head element, in particular a cylinder head, by means of which the working space housing is covered and connected, for example screwed, to each working space housing, a respective working chamber housing head element can be assigned, then the crankcase of the internal combustion engine is advantageously connected to the at least one a Arbeitsraumgehäusekopfelement under mediation of at least one sealing element, in particular a bellows connected, wherein the sealing element is designed so flexible that it also with the relative movement of the working space housing and thus the at least one working space housing head element relative to the crankcase while maintaining the respective connection of the working space housing head element with the Sealing element ensures a seal of the combination of work space housings and crankcase.

In other words, this means that the sealing element thus seals the said composite against leakage, for example, against lubricating oil and / or combustion gases, and this at all possible, adjustable compression ratios of the internal combustion engine according to the invention.

This is made possible, in particular, by the mentioned bellows which, on the one hand, represents a solid sealing element and, on the other hand, has a very high degree of flexibility for the representation of the seal.

The invention also relates to a method for operating a combustion engine in V-construction with a crankcase with two enclosing an angle and at least one working space, in particular a cylinder, the internal combustion engine having working space housings, in particular cylinder housings, wherein the respective working space housing for setting variable compression ratios relative is moved to the crankcase. Advantageous embodiments of the internal combustion engine according to the invention are to be regarded as advantageous embodiments of the method according to the invention and vice versa.

The inventive method thus makes it possible to adjust the compression ratio of the internal combustion engine as needed to a corresponding operating state of the internal combustion engine, for example, an operation of the internal combustion engine at partial load requires a different compression ratio than operating the internal combustion engine at full load to represent a fuel-efficient operation, which low CO ₂ - Emissions means.

At the same time this needs-based and consumption-optimal adjustment of the compression ratio in a simple and thus cost-effective manner possible without affecting moving parts and thus their bearings, which would drive the cost and thus the cost of the internal combustion engine or the process to undesirable heights.

The internal combustion engine according to the invention and the method according to the invention also have the advantage that the relative movement of the working space housing or the at least one working space head element is low, which also keeps the effort to seal the described composite of working space housing and crankcase in a small frame. In addition, the respective working space housing with the same compression ratio can be operated, which thus allows the same combustion conditions in the corresponding work spaces. This also allows a low-consumption and low-emission operation of the internal combustion engine and avoids a compromise in the adjustment of the compression ratio, as would be the case with different compression ratios of the work spaces and a fuel consumption and low-emission operation of the internal combustion engine would adversely affect.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description and features mentioned below in the description of the figures and / or alone in the figures and feature combinations are usable not only in the respectively specified combination but also in other combinations or in isolation without the scope of the invention leave.

The drawings show in:

1 two cross-sectional views of an embodiment of the variable compression ratio internal combustion engine according to the invention, wherein a high compression ratio is set; and

2 two cross-sectional views of the internal combustion engine according to 1 , where a low compression ratio is set.

The 1 and 2 show an internal combustion engine 10 in V-construction with a crankcase 12 in which a crankshaft 14 taken and stored on corresponding journal.

The internal combustion engine 10 has a plurality of cylinder housings 16 and 18 on, in which 1 and 2 two cylinder housings 16 and 18 are shown. The cylinder housing 16 is a first cylinder bank 20 , and the cylinder housing 18 a second cylinder bank 22 assigned, the cylinder housing 16 and 18 each a work space in the form of a cylinder 24 in which a piston 26 according to directional arrows 28 and 30 is held movable. The directional arrows 28 and 30 correlate with the longitudinal extent of the cylinder 24 the cylinder housing 16 and 18 ,

At this point it should be noted that due to the choice of cross-sectional level in the 1 and 2 only the cylinder 24 of the cylinder housing 16 you can see.

Like that 1 and 2 can also be seen close the cylinder housing 16 and 18 and thus the cylinder banks 20 and 22 an angle, whereby the said V-construction of the internal combustion engine 10 is shown.

The cylinder housing 16 and 18 are each through a cylinder head 32 and 34 covered and screwed with these, being in the cylinder heads 32 and 34 Gas exchange valves and corresponding camshafts for controlling these gas exchange valves are stored.

The cylinder housings 16 and 18 associated piston 26 , wherein due to the choice of the cross-sectional plane only the cylinder housing 16 associated pistons 26 in the 1 and 2 is shown are over connecting rods 36 with the crankshaft 14 connected, the connecting rods 36 via a small connecting rod eye and via a corresponding piston pin 38 with the pistons 26 and a big eye with a crankpin 40 the crankshaft 14 are connected. The crankpin 40 is eccentric to the axis of rotation of the crankshaft 14 arranged. As a result, in a known manner, a rotational movement of the crankshaft 14 in a translational movement of the pistons 26 in the cylinders 24 transformable.

To represent variable compression ratios of the internal combustion engine 10 is the respective cylinder housing 16 and 18 relative to the crankcase 12 movable, this mobility by means of journals 42 the crankshaft 14 associated eccentric devices 44 is shown. In the 1 is set at a high compression ratio, which means that a distance s between a respective, through the cylinder heads 32 respectively 34 formed combustion chamber roof of the cylinder 24 and a respective, the cylinder heads 32 respectively 34 facing end face of the piston 26 is very low when the pistons 26 are in their respective top dead centers. This leads to a high compression of one in the respective cylinder 24 provided working gas.

For sealing the composite of crankcase 12 and cylinder housing 16 and 18 is the crankcase 12 with the cylinder heads 32 respectively 34 under the mediation of a respective bellows 46 connected to the internal combustion engine 10 against leakage of lubricating oil and into the crankcase 12 escapes evolved combustion gases. The bellows 46 are in accordance with the 1 in a contracted position.

By a rotation of the eccentric devices 44 for example, according to a directional arrow 48 is a lower compression ratio of the internal combustion engine 10 feasible, which according to the 2 is shown.

The cylinder housing 16 and 18 be parallel to their longitudinal extent according to the directional arrows 28 respectively 30 relative to crankcase 12 from the crankcase 12 moved away. Since the relative position of the crankshaft 14 due to the fixed bearing of the crankshaft 14 in the crankcase 12 remains the same, there is an increase in the distance s between the described end face of the respective piston 26 and the respective combustion chamber roof, resulting in a low compression of the working gas and thus a low compression ratio of the internal combustion engine 10 results.

As based on the 2 is also clear, are now the bellows 46 in one opposite the 1 stretched position around the sealing of the composite crankcase 12 and the cylinder housings 16 and 18 to ensure.

Another advantage of the internal combustion engine 10 is that the crankshaft 14 coaxial with an input shaft of an internal combustion engine 10 associated transmission is arranged and can also remain arranged and that even at different compression ratios of the internal combustion engine 10 , as there is no change in the relative position of the crankshaft 14 to the crankcase 12 he follows.

Like that 1 and 2 it can be seen, are the eccentric 44 coaxial to the crankshaft 14 arranged and supported on this and stored, resulting in a direct flow of power from the crankshaft to the cylinder housing 16 and 18 or vice versa and thus prevents a complicated flow of force. This is the reliability of the internal combustion engine 10 conducive because moving parts and thus their bearings in the setting of the corresponding compression ratio are not affected or must be affected, which is the cost of the internal combustion engine 10 and keeps its complexity to a minimum. The internal combustion engine 10 Therefore, with optimal and needs-based adjustability to respective operating conditions has a high reliability and low probability of failure. In addition, the operation of both cylinder banks 20 and 22 ensured with the same compression ratios, which is the same combustion conditions in the respective cylinder 24 allows to represent a fuel consumption and low-emission operation.

LIST OF REFERENCE NUMBERS

10

Internal combustion engine

12

crankcase

14

crankshaft

16

cylinder housing

18

cylinder housing

20

cylinder bank

22

cylinder bank

24

cylinder

26

piston

28

arrow

30

arrow

32

cylinder head

34

cylinder head

36

pleuel

38

bolt

40

crank pins

42

pivot

44

eccentric

46

bellow

48

arrow

s

distance

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1245803 A1 [0002]

Claims (10)

Internal combustion engine ( 10 ) in V-construction with a crankcase ( 12 ) and with two, an angle enclosing and in each case at least one working space ( 24 ), in particular a cylinder ( 24 ), the internal combustion engine ( 10 ) having working space housings ( 16 . 18 ), in particular cylinder housings ( 16 . 18 ), characterized in that the respective working space housing ( 16 . 18 ) relative to the crankcase ( 12 ) is movable. Internal combustion engine ( 10 ) according to claim 1, characterized in that the respective working space housing ( 16 . 18 ) by means of at least one of the respective working space housing ( 16 . 18 ) associated eccentric device ( 44 ) is movable. Internal combustion engine ( 10 ) according to claim 2, characterized in that the eccentric devices ( 44 ) according to the through the work space housing ( 16 . 18 ) enclosed angle to each other. Internal combustion engine ( 10 ) according to one of claims 2 or 3, characterized in that the eccentric devices ( 44 ) at one of the crankcase ( 12 ) at least partially recorded crankshaft ( 14 ) are supported. Internal combustion engine ( 10 ) according to one of claims 2 to 4, characterized in that the eccentric devices ( 44 ) substantially coaxial with the crankshaft ( 14 ) are arranged. Internal combustion engine ( 10 ) according to one of the preceding claims, characterized in that the working space housing ( 16 . 18 ) in an adjustment of the eccentric devices ( 44 ) by substantially equal amounts relative to the crankcase ( 12 ) are moved. Internal combustion engine ( 10 ) according to one of the preceding claims, characterized in that the internal combustion engine ( 10 ) has a setting. Internal combustion engine ( 10 ) according to one of the preceding claims, characterized in that at least one torque support device between the working space housings ( 16 . 18 ) and the crankcase ( 12 ) is provided. Internal combustion engine ( 10 ) according to claim 6, characterized in that the crankcase ( 12 ) with the working chamber housing head element ( 32 . 34 ) mediating at least one sealing element ( 46 ), in particular a bellows ( 46 ), connected is. Method for operating an internal combustion engine ( 10 ) in V-construction with a crankcase ( 12 ) and with two, an angle enclosing and in each case at least one working space ( 24 ), in particular a cylinder ( 24 ), the internal combustion engine ( 10 ) having working space housings ( 16 . 18 ), in particular cylinder housings ( 16 . 18 ), characterized in that the respective working space housing ( 16 . 18 ) for setting variable compression ratios relative to the crankcase ( 12 ) is moved.

Images